Crutch, cane, &amp;c.



INVENTUR Patented Sept. 30, |902.

Filza'. A

P. W. PRATT.

CRUTCH', CANE, 6m. (Application filed. Feb. 27, 1902.)

No. 7|0,o74.

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UNTTEDY STATES PATENT OEEICE.

x PHILIP W. PRATT, OF BOSTON, MASSACHUSETTS.

' oRUToH, CANE, sbc.

SPECIFICATION forming part of Letters Patent No. 710,074, dated September 30, 1902.

Application iiled February 27, 1902. Serial No. 95,916. (No model.)

clinedfat various angles relatively to the plane of the surface on which it bears, the treadpiece at the same time remaining parallel with said surface and having a suitably-extended bearing thereon.

The inventionhas for its object to provide improved means for connecting a crutch stick or body with an elastic tread-piece in order to permit an oscillatory motion of one part relatively to the other.

The invention consists in the improvements which I will now proceed to describe and claim. y

Of the accompanying drawings, forming a part of this specication, Figure 1 represents a side elevation of thelower portion of a crutch stick or body and an elastic tread-piece connected therewith. Fig. 2 represents a section on line 2 2 of Fig. l. Fig. 3 represents an edge view of the foot shown in Fig. 2 embedded in the elastic tread-piece. Figs. 4 and 5 represent sectional views of different embodiments of my invention. Fig. 6 represents a sectional View of another embodiment of the invention. Fig. 7 represents a side elevation of the hinged tread-piece-engaging clamp shown in Fig. 6. Fig. 8 represents a sectional view of another embodiment of the invention. Fig. 9 represents a sectional View showing a modification. of one of the parts shown in Fig. 9.

The same reference characters indicate the same parts in all the igures.

Referring for the present to Figs. 2 and 4, Ct represents the lower portion of a crutch stick or body, and a. represents a ferrule attached to the body a.

b represents an annular socket member affixed to the ferrule ct, said socket member being formed internally as a zone or section of a hollow sphere and having an upwardly- Fig. l0 represents a plan Viewv .projecting externally-threaded flange b', which is engaged with an internal thread in the ferrule a and surrounds an opening b2, which opening is surrounded by the annular socket member b.

c represents a com plemen tal member-,which for convenience I term a ball member, the same presenting a zone or segment of a sphere which is adapted to oscillate in the socket member b.

d represents a stud which is affixed rigidly to the ball member c and projects upwardly Y therefrom through the opening b2, said stud being provided with a head d at its upper end.

e represents a spring which is interposed between the head d and an abutment within the ferrule et', said abutment being in this case the upper end of the flange 'b'. The spring exerts a constant upward pressure on the stud CZ and through the latter holds the ball member @with a yielding pressure against the socket member b. The stud d is enough smaller than the opening b? and the interior Vof the ferrule a to permit the stud to oscillate laterally or to permit the ferrule and crutch-body ct to oscillate laterally on the ball member c, so that the crutch-body can be vinclined relatively to thetread-piece hereinafter described, asindieated by dotted lines in Fig. 2.

j' represents an elastic or frictional treadpiece which is affixed to the ball member c and has a bottom surface suitably formed to 'constitute the tread of the crutch.

It will be seen that the above-described ball-and-socket members, one affixed to the tread-piece and the other to the crutch-body, and the means for holding said members in yielding engagement and for permitting an oscillatory movement of the crutch-body relatively to the tread-piece, enables the treadpiece to maintain a square and firm bearing on the pavement, door, or other surface on which it bears regardless of the inclination of the crutch-body. The crutch-body can therefore swing in the various directions required by the movements of the user without requiring a corresponding swinging or tilting of the tread-piece.

The details of construction of a crutch or cane embodying the invention above de- IOO scribed may be variously modified. In Figs. 2 and 4C I show the stud d provided with a screw-threaded extension, which is engaged with an internal thread formed in the ball member c, the stud and ball member being thus rigidly connected. ed extension of the stud d terminates just below the under surface of the ball member and is of only suiicient length to receive a nut d2, which bears against the under surface of the ball member. In Fig. 2 I show the treadpiecefaffixed to the ball member by means of an internally-threaded shank g, which is embedded in the upper portion of the treadpiece and bears at its upper end on the under side of the ball member c. A nut g, engaged with a reduced threaded extension at the lower end of the stud d, holds the shank g against the ball member c. A circular footpiece g2 is preferably held by the nut g against the .lower end of the shank g, said shank and footpiece being both embedded in the unvulcanized composition of which the tread-piece is iliade and secured therein by the process 0f vulcanization. 'lhe tread-piece is provided with a central openingf, through which access can be had to the nut g', the latter having a slotted lower portion to engage a screw-driver or other tool. The removal of the nut g enables the tread-piece to be disconnected from the stud extension by nnscrewing it therefrom.

In 4 I show the tread-piece fsecured to the ball member c by means of an externally-screw-threaded stem f2, formed on and integral with the tread-piece, and an internally-threaded downwardly-projecting ange c', formed on the ball member c. To support the screw-thread on the stem f2 and prevent it from yielding too freely, I insert a metallic stiiening-tubef3 in the stemfg. The construction shown in Fig. 6 is practically like that shown in Figs. 2 and 4 so far as the engagement of the stud d with the ball member c is concerned, and the ball member is provided with an internally-threaded flange c', substantially as shown in Fig. 4. In this modification, however, the tread-piece fis connected with the ball member by means of an intermediate clamp composed of two parts t' t", hinged together at i2. The lower portions of said members are formed as jaws, adapted to encircle a shouldered portion of the tread-piecef, their upper portions being externally threaded and collectively forming ashank adapted to engage the internal thread of the flange c.

In Fig. 5 I show the socket member b entirely contained within the ferrule ct/ and screwed directly into an internally-threaded sleevej', formedl on a iiangej, which is affixed to the ferrule a. The ball member cis formed on the upper end of a tubular shank c3, which projects downwardly and is engaged with the tread-piecefin the same manner that the shank g (shown in Fig. 2) is en- In Fig. 4 the thread-- gaged. The under side of the flangej is concave and receives a cancavo-convex washer 7o, which tits the under side of the flangej and the upper end of the tread-piece f. The elasticity of the tread piece enables the crutch-body to oscillate upon the tread-piece, any inclination of the crutch-body from a vertical position causing one side of the iiangejl to move inwardly and compress the corresponding side of the upper portion of the tread-piece. The upper portion of the treadpiece is made suitably yielding by the formation of a cavityf4, which surrounds the lower portion of the tubular shank csand reduces the thickness of the portion of the tread -piece which is pressed upon by the Hangs j when the crutch-bodyis inclined. In Fig. 8 I show a construction which is substantially similar to that shown in Fig. 5, exceptingin the following particulars, namely: The threaded extension of the stud d is carried down below the tubular shank formed on the ball membercand engaged with anut g', substantially such as is shown in Fig. 2, the nut confining a sleeve m and one or more washers n, said sleeve and washers constituting an extension of the tubular shank c3, formed on the ball member c.

The footpiece g2, embedded in the body of the tread-piecef and secured to the shank d, provides a strong and durable connection between the said treadpiece and shank. The said footpiece shown in Figs. 2, 3, 5, and Sis composed of metal, while the footpiece shown in Fig. 9 is an annulus or washer of canvas or other strong flexible material clamped at its inner edge between two shouldered collars g3g, which are held by the nut g@ The flexibility of the footpiece shown in Fig. 9 materially increases the elasticity of the tread-piece f.

I claiml. A crutch or cane comprising a body having a rigid annular socket member atits lower portion, a ball member fitted to oscillate in said socket member, a stud aftixed rigidly tothe ball member and projecting therefrom through the opening of the socket member and movable laterally therein, a spring engaged with said stud and with a fixed abutment within said body, said spring and stud holding the ball member yieldingly against the socket member and permitting one member to oscillate on the other, and an elastic tread secured to the ball member.

2. A crutch or cane comprising a body having a rigid annularsocket member at its lower portion, a ball member fitted to oscillate in said socket member, a stud axed rigidly to the ball member and projecting therefrom through the opening of the socket member and movable laterally therein, a spring engaged with said stud and with a fixed abutment within said body, saidspringand stud holding the ball member yieldingly against the socket member and permitting one member to oscil- IOO late on the other, an elastic tread, and means -for detachably securing the said tread to the ball member.

3. A crutch or cane comprising a body having a rigid annular socket member at its lower portion, a ball member fitted to oscillate in said socket member, a stud affixed rigidly to the ball member and projecting therefrom through the opening of the socket member and movable laterally therein, a spring engaged with said stud and with a fixed abutment within said body, said spring and stud holding the ball member yieldingly against the socket member and permitting one member to oscillate on the other, a shank attached to and extending downwardly from the ball member, and an elastic tread attached to said shank.

4. A crutch or cane comprising a body having a rigid annular socket member at its lower portion, a ball member fitted to oscillate in said socket member, a stud affixed rigidly to the ball member and projecting therefrom through the opening of the socket member and movable laterally therein, a spring engaged with said stud and with a fixed abutment Within said body, said spring and stud holding the ball member yieldinglyagainst the socket member and permitting one member to oscillate on the other, a shank attached to and extending downwardly from the ball member and provided with a footpiece at its lower portion, and an elastic tread attached to said shank and footpiece.

5. A crutch or cane comprising a body'having a rigid annular socket member at its lower portion, a ball member fitted to oscillate in said socket member, a stud affixed rigidly to the ball member and projecting therefrom through the opening of the socket member and movable laterally therein, said stud having a threaded extension projecting down- Wardly through and below the ball member, a spring engaged with said stud and with a fixed abutment within said body, said spring and stud holding the ball member yieldingly against the socket member and permitting one member to oscillate on the other, a tubular shank engaging said threaded extension, and an elastic tread attached to saidshank.

6. An elastic tread-piece provided with a rigid attaching member embedded in the tread-piece, and a flexible footpiece secured to the inner end of said attaching member and having its marginal portion embedded in the tread-piece.

Y In testimony whereof I have affixed my signature in presence of two witnesses.

PHILIP W. PRATT. Witnesses:

. C. F. BROWN,

E. BATCHELDER. 

